Method of and apparatus for threading in threads on drawtwisting or drawwinding machines,and improved knot used in the performance of said method

ABSTRACT

THERE IS DISCLOSED AN IMPROVED METHOD OF AND APPARATUS FOR THREADING IN THREADS ON DRAWTWISTING OR DRAWWINDING MACHINES OR SIMILAR MACHINES. ACCORDING TO THE INVENTION THE THREAD IS SEVERED BETWEEN AN UNDRAWN CREEL PACKAGE WHICH IS BECOMING EXCHANGED AND A THREAD FEED MECHANISM AND THE THREAD END RUNNING OR EXTENDING TOWARDS THE FEED MECHANISM IS HELD IN A READY OR PREPARATORY POSITION, THE CREEL PACKAGE WHICH IS BEING EXHAUSTED IS REPLACED BY A FULL CREEL PACKAGE AND A CONNECTION IS ESTABLISHED BETWEEN THE THREAD END OF THE FULL CREEL PACK-   AGE AND THE AFOREMEMTIONED THREAD AND EXTENDING TOWARDS THE FEED MECHANISM. ACCORDING TO AN IMPORTANT ASPECT OF THE INVENTION, THE DRAWING RATIO IMPRATED TO THE THREAD IS REDUCED DURING SUCH TIME AS THE PREVIOUSLY ESTABLISHED THREAD COMMECTION PASSES THROUGH KA DRAWING ZONE. THERE IS ALSO DISCLOSED AN IMPROVED KNOT FOR THE CONNECTION OF THE THREAD ENDS WHICH PROVIDES ONE TECHNIQUE OF REDUCING THIS DRAWING RATIO WITHOUT THE AID OF MECHANICAL MEANS.

Oct. 12, 1971 JAEGGLI 3,611,694

METHOD OF AND APPARATUS FOR THREADING IN THREADS 0N DRAWTWISTING OR DRAW-WINDING MACHINES, AND IMPROVED KNOT USED IN THE PERFORMANCE OF SAID METHOD Filed Aug. 1, 1969 5 Sheets-Sheet 1 BY 4:44., W

, mN-M Oct. 12, 1971 R JAEGGLI 3 ,611,694

METHOD OF AND APPARATUS FOR THREADING IN THREADS ON DHAWTWISTING OR DRAWWINDING MACHINES, AND IMPROVED KNOT USED IN THE PERFORMANCE OF SAID METH Filed Aug. 1, 1969 OD 5 Sheets-Sheet m w 1 h V M W G a h J F L 0 U U K y; L w

R. JAEGGLI 3,611,694 METHOD OF AND APPARATUS FOR THREADING IN THREADS DN DRAWTWISTING OR DRAWWINDING MACHINES, AND IMPROVED Oct. 12, 1971 KNOT USED IN THE PERFORMANCE OF SAID METHOD 5 Sheets-Sheet 5 Filed Aug. 1, 1969 IN, W a N G M J F L D D H BY W 0d. 12, 1971 R JAEGGLI 3,,61L94 METHOD OF AND APPARATUS FOR THREADING IN THREADS 0N DRAWTWISTING OR DRAW-WINDING MACHINES, AND IMPROVED KNOT USED IN THE PERFORMANCE OF SAID METHOD Filed Aug. 1, 1969 5 Sheets-$heet 4.

INVIL'N'I (1R4 i!" 12, 1971 R JAEGGL] flmfl METHOD OF AND APPARATUS FOR THREADING IN THREADS 0N DRAWTWISTING OR DRAW-WINDING MACHINES, AND IMPROVED KNOT USED IN THE PERFORMANCE OF SAID METHOD Filed Aug. 1, 1969 5 Sheets-Sheet 5 III ELIHHH 1| HHHHH J llllll|lllllllll|l u mumunmETHlllHIHI IHHHIIE United States US. Cl. 57-34 25 Claims ABSTRACT OF THE DISCLOSURE There is disclosed an improved method of and apparatus for threading in threads on drawtwisting or drawwinding machines or similar machines. According to the invention the thread is severed between an undrawn creel package which is becoming exhausted and a thread feed mechanism and the thread end running or extending towards the feed mechanism is held in a ready or preparatory position. The creel package which is being exhausted is replaced by a full creel package and a connection is established between the thread end of the full creel package and the aforementioned thread and extending towards the feed mechanism. According to an important aspect of the invention, the drawing ratio imparted to the thread is reduced during such time as the previously established thread connection passes through a drawing zone. There is also disclosed an improved knot for the connection of the thread ends which provides one technique of reducing this drawing ratio without the aid of mechanical means.

BACKGROUND OF THE INVENTION The present invention relates to a new and improved method of threading in threads on drawtwisting or drawwinding or similar machines, further concerns an apparatus for implementing the inventive method.

In known drawtwisting or draw-winding processes the undrawn thread normally passes from a creeled package via thread brakes and thread guides into a feed mechanism driven at constant circumferential speed. Subsequently this thread is wrapped in a plurality of wraps around a draw roll also driven at constant speed. Between the feed mechanism and the draw roll the thread is drawn to several times its original length. Thereafter the drawn thread is Wound onto a spindle or onto a cross-wound bobbin. Drawing also may be effected in more than one drawing zone as well as with the help of drawing pins and heating devices.

Normally the creeled bobbins hold a quantity of thread sufiicient for filling a plurality of drawtwisting or drawwinding bobbins. It is a known procedure to stop the drawtwisting or draw-winding machine for dofiing the full packages and donning empty tubes and to restart the machine without the need of re-threading all the threads. This procedure, however, is applicable only, as long as the creel packages do not need to be changed. If a creeled package is emptied so far that the rest of the undrawn thread left on it will not yield another full drawtwisting or draw-winding bobbin, then the thread is severed and a new package is creeled in. After creeling the machine is started up and each thread is threaded into all working elements manually. This operation requires more personnel than otherwise needed for controlling machine operation. Another disadvantage of the procedure mentioned is that at least the first set of drawtwisting or draw-winding bobbins produced from a new set of creel packages will not contain the same length of thread as the threads successively must be threaded in at one position after the other. A procedure, however, also is known in which the threads are threaded in while the machine is running slowly and are wound onto waste packages, waste cones or similar devices. Threading in. the threads while the machine runs slowly at crawling speed, however, requires still more manual work.

Furthermore, in the textile industry techniques are known for winding the innermost thread end of a package so that it is easily accessible as a thread reserve or transfer tail and can be connected to the outermost thread end of a subsequent package in further processes. Also on drawtwisting machines the winding of transfer tails onto the tubes is known. This procedure is, however, not applicable for producing undrawn thread packages for three reasons:

(a) The innermost layers of the undrawn thread packages usually are of a somewhat different quality. They must be considered as waste and must be eliminated.

(b) The thread packages must be free of knots which is not ensured as the length contained on the undrawn thread packages is variable.

(c) The known connecting knots result in thread breakages if the thread is drawn under normal drawing conditions.

SUMMARY OF THE INVENTION Accordingly, it is a primary objective of the present invention to reduce the manual work and maintain constant thread length on each thread package produced on a drawing machine. This goal is achieved, and the aforementioned disadvantages are eliminated, by means of the method according to the invention for threading in threads on drawtwisting, draw-winding or similar machines, in which, starting from an undrawn creel package, while all threads are severed between the creel package which is becoming exhausted and the thread feed mechanism, and while all thread ends running towards the feed mechanism are held ready, the creel packaeg being exhausted is replaced by a full package, then a connection between the two thread ends is established, and thereafter the drawing ratio imparted to the thread is reduced while the previously established connection passes through the drawing zone.

The apparatus for implementing the method according to the invention is generally manifested by means for temporarily reducing the drawing ratio.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be better understood, and objects other than those set forth above, will become apparent, when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein:

FIG. 1 is a schematic view of the thread path on a drawtwisting machine;

FIG. 2 is a perspective view showing details of a thread cutting and holding device;

FIG. 3 is a schematic side view of a drive cabinet of a drawtwisting machine;

FIG. 4 is a perspective view of a lifting device for the pressure roll of a thread feed or delivery mechanism;

FIG. 5 is a perspective view of a drawing zone;

FIG. 6 illustrates details of a preferred form of knot connecting two thread ends;

FIG. 7 is a side view of an alternative design of the drive cabinet shown in FIG. 3;

FIG. 8 is a side view of another embodiment of the drive cabinet shown in FIG. 3; and

FIG. 9 depicts an alternative design of drawing zone according to FIG. 5.

DE' I'AILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Describing now the drawings, it will be recognized from FIG. 1 that an undrawn thread 2 pulled off a creeled package 1, composed of one or a plurality of endless filaments, passes a stationary thread guide 3, a cutting and holding device 4, a thread brake 5. Then thread 2 passes onto a thread feed or delivery mechanism consisting of a single pressure roll 6 and a delivery roll 7 extending along the length of the machine. Pressure roll 6 is equipped with detachable loading means, here shown designed as a pivotable loading arm 8. The thread 2 passes through the nip formed by these two rolls 6 and 7 at a low feed velocity or speed V and by means of drawing roll 9 and separator or deflector roll 10 this thread 2 is taken oif at a speed V which is three to four times higher than V drawing of the thread thus being effected. In many cases, this process is carried out while using an intermediately disposed drawing pin 11.

Subsequently, the thread 2 passes through a traveller 12 slidably arranged upon a ring 13 traversing up and down and is transferred onto a tube or sleeve 14 where it is wound into a thread package 15. Below tube 14 a waste cone 17 is arranged on spindle 16 down to which section of the spindle 16 the traveller ring 13 is temporarily lowered for the formation of a waste bunch 18. The twist imparting winding mechanism consisting of spindle 16, ring 13 and traveller 12, described here with reference to the example of a drawtwisting machine, of course, can be replaced by a winding mechanism not imparting twist, such as conventionally used on draw-winding machines. I As best seen by referring to FIG. 2, the thread cutting and holding device 4 consists of a stationary rail 19 extending along, and fixed to, the machine frame, and a rail or rod 20 arranged slidably along rail 19. Each rail 19 and 20 is provided with a blade 21 and 22, respectively, the latter further being equipped with a thread clamping device 23, as shown, which contacts the edge 24 of the other blade 21 and clamps the thread end extending or running towards the thread brake 5.

On a machine such as that described and incorporating a large number of such processing stations or positions, the following technique is utilized: If a predetermined thread length is wound onto the thread package the machine is stopped and the thread is held in known manner on the spindle 16 while the full thread packages 15 are exchanged against empty tubes 14. If the creeled packages 1 are emptied so far that not enough material is left for filling a whole thread package 15, then the thread 2 at each processing position is severed by means of the cutting and holding device 4 between the creeled package 1 and the feed mechanism 7 and the thread end connected to each such feed mechanism (FIG. 2) is held ready by the associated thread clamping device 23 for knotting. Subsequently, the not quite depleted creel packages 1 are replaced by new full creel packages. The respective thread ends of the new creel packages 1 are threaded through the thread guide 3 arranged in front of the cutting point and are connected to the thread end held ready by the cutting and holding device 4 by means of, for instance, a knot, a welding or an adhesive bond. During the subsequent startup of the machine the drawing ratio is reduced by suitable means, described in greater detail later on, at least while the connection or attachment location of the two thread ends passes through the drawing zone, so that no thread break occurs. This connection location or point subsequently is wound onto waste cone 17 into waste bunch 18, rather than onto the thread package 15. Additionally, the entire passage of the thread connection point may take place while the machine is running slowly at crawl speed. The previously mentioned reduction of the drawing ratio, while the thread connection point passes through the drawing zone, can be effected by means of the following exemplary devices: In the embodiment according to FIG. 3, a drive cabinet of a drawtwisting machine with the feed mechanism drive and with the draw roll drive is illustrated. The main drive motor 25 drives the spindle drive shaft 26 and, via two gears 27 and 28, the drive shaft 29 of the draw rolls 30. On shaft 29 there are also arranged two more gears 31 and 32 which mesh with gears 34 and 35, respectively, arranged to be freely rotatable upon feed roll shaft 33. A disc 36 is fixed on shaft 33. Adjacent to each of the gears 34 and there is an electrically operated disc-clutch 37 and 38, respectively, for either coupling the gear 34 arranged on the left-side or the gear 35 arranged on the right-side with the disc 36, depending upon the position of a switch 39 controlling the current supply. If the gear 34 arranged on the left-side is coupled (switch position indicated with dashed lines), owing to the gear tooth ratio of gears 31 and 34 transmitting the rotational momentum, the feed roll shaft 33 turns faster and the drawing ratio between feed mechanism 33' and draw rolls 30 thus is reduced. Once the thread connection point has passed, then the switch 39 is brought into normal operating position (solid lines) in which feed roll shaft 33 is driven via the gears 32 and '35, the drawing ratio being normal again. Directly after the drive motor 25 a selectively operable reduction gear box 40 can be inserted into the drive train, if needed, permitting a slow or crawl motion of the machine. This design proposal also may be selected for draw-windingmachines as the winding speed is not affected by reduction of the drawing ratio.

Another embodiment of the invention, as shown in FIG. 4, permits the change in drawing ratio by means of lifting the pressure roll of the feed mechanism. Pressure rolls 41, which in the arrangement of FIG. 4 rest upon feed roll 42 under their own weight, are arranged to be freely pivotable on shaft 44. A carrier lever 45 fixed on this shaft 44 reaches under the associated support arm 43, and by turning shafts 44 by means of a crank 48 via tWO mutually meshing gears 46 and 47 these pressure rolls 41 are thus lifted off the associated feed or delivery roll 42. A ratchet 49, or equivalent structure secures arms 43 in the lifted position. In order to reduce the drawing ratio it is only necessary to turn crank 48 clockwise until carrier lever 45 lifts associated arm 43 somewhat, so that the corresponding pressure roll 41 is lifted from the feed or delivery roll 42 and thread 51 at the speed V is withdrawn from the package creeled above (not shown). The drawing ratio, in a very simple manner, is thus reduced to zero without any change of the winding speed. Once the thread connecting point has passed out of the drawing zone, the ratchet 49 is manually lifted so that pressure rolls 41 under the influence of their own Weight again contact the associated delivery roll 42 and since pressure is re-established in the nip, the drawing ratio goes back to normal.

Still a further embodiment suitable for drawtwisting machines is shown in FIG. 5. On the outer part of draw rolls 52 there is provided a zone of low friction 53, for instance a sand blasted zone. If the thread 54 is placed there (yarn path indicated in dashed lines) the circumferential speed of the draw rolls 52 is not transferred to the thread 54 owing to slippage at zone 53, that is, the' thread moves at the feed speed V towards the winding position (not shown). No drawing action thus takes p ace. Shifting of the thread 54 along the associated'draw roll 52 is effected quite simply by moving a rail 55 or equivalent structure, on which a plurality of thread guide elements, e.g. drawing pins 56, are mounted, so far to the outside that thread 54 is guided onto zone 53. This movement is effected by a suitable motor 57 provided with a reduction gear arrangement 58 and driving a shaft 59 on which there are provided control cam disc 60 and suitably shaped control cams 61. Cam disc 60 activates a switch 62 controlling drive motor 57 which after the connection of the thread ends is established is started by hand, and after half a revolution of shaft 59 is stopped again by the next cam passing and activating the switch button 63.

the

Rods 66 rigidly connected to rail 55 are arranged horizontally slidable in a housing 65 of the frame and are pressed against cam disc 61 by springs 64. Motor 57 turns shaft 59 half a revolution or turn so that rail 55 moves outwardly into the position indicated by dash-dotted lines and remains there until the thread connection point has left the drawing zone. Shortly before shaft 59 has completed its half revolution the original condition is again established, that is to say, the thread is again guided onto the zone of high friction of the associated draw roll 52 (thread path indicated with solid lines) from the feed roll. The drawing ratio thus again corresponds to the original value. This design would not be feasible for drawwinding machines as the winding speed cannot be reduced to the feed speed V without difficulties.

Another example of the invention provides reduction of the drawing action without mechanical means, but provides a thread connection of such extensibility that a normal drawing action can not take place. This is achieved, for example, by incorporating a thread reserve into the thread connection, as best seen by referring to FIG. 6. The thread end 67 running out is knotted in such manner that the end 68 of the new thread can slide in it, but catching on of the connection or attachment location at the thread guide elements, however, is not possible. The end 68 of the new thread forms a loop 69 as a thread reserve through knot 70 in the thread end 67 running out and is tied on itself in a slidable knot 71, a thread length L being provided which can be used up while knot 71 moves toward knot 70 during the passing of the thread connection location through the drawing zone. Friction conditions in knots 70 and 71 are chosen such that loop 69 is not pulled out while it passes through the thread guide elements in front of the feed mechanism, but that after passing the feed mechanism, however, and before reaching the drawing pin, sliding occurs already such that the knot moves around the drawing pin without being tensioned by the full drawing tension. The same procedure also is applicable in a drawing zone without a drawing in. p An alternative design, comparable to the arrangement according to FIG. 3, is shown in FIG. 7. Here, gear 72 can be coupled to shaft 73 by means of a clutch 79 which is activated and released by switch 74. If the feed mechanism is uncoupled by switch 74 and pressure rolls 75 remain weighted, the threads 76 drag the feed mechanism, the threads being subject to an elastic deformation only as e.g. in processing of heavy denier threads, or the braking momentum acting on the feed mechanism due to friction in the bearings generates tensions in the thread sufficient for partial drawing. This might be the case if finer denier threads are processed. Somewhat higher thread tensions are generated if the inertia of the feed rolls is an influencing factor. This is the case if the machine is speeded up to normal operating speed while the thread connection passes through the drawing zone, in which case the feed mechanism must be accelerated by the tension on the threads exclusively.

A further embodiment is shown in FIG. 8. Here a first drawing phase e.g. with a thread drawing ratio ranging from 1.004 to 1.5 is effected in a drawing zone I between feed mechanism 172 and a first draw roll 173 rotating at high speed, whereupon a second, major drawing phase follows, for instance, with a thread drawing ratio ranging from 4 to 2.8, in a drawing zone II ending at draw roll 174. Other than in the embodiment according to FIG. 3 an analogous arrangement comprising a clutch 177 coupling alternatively gears 175 or 176 here is used to reduce the drawing ratio in the drawing zone II to e.g: a ratio of 2, if gear 175 is coupled to disc 178 which is fixed on shaft 179. The drawing ratio in the zone I being smaller anyhow, can remain unchanged as the danger of thread breakage due to excessive tension in the knot passing through the drawing zone is relatively small at low drawing ratios. This design also is suitable for draw-winding machines, as the speed of the thread leaving draw roll 174 is not influenced.

A further advantageous application of the principle shown in FIG. 5 can be used on a draw twisting machine equipped with a drawing and a relaxing zone, as schematically shown in FIG. 9. Between feed mechanism 80 and draw roll 81 the thread is drawn in drawing zone I and subsequently is relaxed by roll 82 rotating at lower speed in relaxing zone II. If the thread is guided onto the region or zone 83 of lower friction of roll 81 (thread path indicated by dash-dotted lines) slippage of the thread on this roll occurs and drawing no longer takes place. In zone II also no more relaxation can thus take place since an undrawn thread can not relax. As the thread is guided onto the zone 83, the thread on roll 82 also moves onto the zone 84 of the lower friction provided here also, so that the thread also leaves this roll 82 at the feed speed and thread accumulations in the relaxing zone are avoided.

It should be apparent from the foregoing detailed description, that the objects set forth at the outset to the specification have been successfully achieved.

What is claimed is:

1. A method of threading in threads on drawtwisting, draw-winding or similar machines comprising the steps of:

(a) severing the thread between an undrawn creel package which is becoming exhausted and a thread feed mechanism;

(b) holding the thread end extending towards the thread feed mechanism in a preparatory position;

(c) replacing the creel package which is becoming exhausted by a full creel package;

((1) establishing a connection between the thread end of the full creel package and said thread end extending towards the thread feed mechanism; and

(e) reducing the drawing ratio imparted to the thread while the previously established thread connection passes through a drawing zone.

2. The method of claim 1, wherein the step of reducing the drawing ratio imparted to the thread is effected by reducing the difference in the circumferential speeds of the rolls defining the drawing zone.

3. The method of claim 1, wherein the step of reducing the drawing ratio imparted to the thread is effected by increasing the speed of the feed mechanism.

4. The method of claim 1, wherein the step of reducing the drawing ratio imparted to the thread is effected by increasing the speed of the feed mechanism by means of the tension in the thread.

5. The method of claim 4, wherein the tension in the thread is additionally increased by acceleration of the drawing mechanism.

6. The method of claim 1, wherein the step of reducing the drawing ratio imparted to the thread is undertaken by inducing slippage on the feed roll of the feed mechanism.

7. The method of claim 1, wherein the step of reducing the drawing ratio imparted to the thread incorporates the step of tying a thread reserve into the connection of the thread ends.

8. The method of claim 7, wherein the thread reserve is formed by tying a knot on the thread end held in preparatory position and a loop of the new thread end is pulled through said knot which allows thread slippage, then tying the new thread on itself at half the reserve length by a knot which also allows thread slippage.

9. The method of claim 6, further including the step of additionally inducing thread slippage on a subsequent roll forming a relaxing zone.

10. The method of claim 1, including the step of subjecting the thread to a drawing a-ction imparted to such thread in two phases, wherein during the first phase a smaller part and in the second phase a large part of the drawing ratio is applied, and reducing the drawing ratio during the second phase while the thread connection passes through the drawing zone.

11. The method of claim 10, including the step of maintaining substantially constant the smaller part of the drawing ratio applied during said first phase.

12. The method of claim 1, including the step of winding the portion of the thread containing the thread connection separately from the thread package.

13. An apparatus for threading in threads on drawtwisting, draw-winding and similar machines, comprising a driven feed mechanism and a draw mechanism defining at least one drawing zone, and means for reducing the drawing ratio imparted to a thread during such time as a thread connection location thereof passes through said drawing zone.

14. An apparatus as defined in claim 13, wherein said means incorporates clutch means for interrupting the driving action imparted to said feed mechanism.

15. An apparatus as defined in claim 13, wherein said means includes a gear drive which alternatively can be coupled for driving said feed mechanism at increased s eed.

16. An apparatus as defined in claim 13, wherein said feed mechanism includes feed roll means, said reducing means incorporating pressure roll liftably arranged on said feed roll means of said feed mechanism.

17. An apparatus as defined in claim 13, wherein said draw mechanism includes a draw roll processing zone of reduced friction, said reducing means embodying mechanism for changing the thread path temporarily and guiding the thread onto said draw roll zone of reduced friction.

18. An apparatus as defined in claim 17, wherein said mechanism for changing the thread path incorporates a drawing pin.

19. An apparatus as defined in claim 13, wherein means are provided such that said means for reducing the drawing ratio are centrally activated for all threads on a machine.

20. An apparatus as defined in claim 13, further including a thread severing device adapted to be arranged between a creeled package and said feed mechanism.

21. An apparatus as defined in claim 20, wherein said thread severing device serves for simultaneously severing a plurality of threads.

22. An apparatus as defined in claim 20, wherein said severing device embodies a clamping device for a thread end extending towards said feed mechanism.

23. An apparatus as defined in claim 13, wherein said draw mechanism incorporates a first draw roll and a second draw roll, said feed mechanism and said first draw roll defining a first drawing zone and said first and second draw rolls defining said second drawing zone, said means for reducing the drawing ratio incorporating mechanism which alternately can be coupled for driving said first draw roll of said second drawing zone and said feed mechanism of said first drawing zone at increased speed.

24. The method of claim 1, wherein the step of reducing the drawing ratio imparted to the thread is undertaken by inducing slippage on a draw-roll of a drawing mechanism.

25. The method of claim 24, further including the step of additionally inducing thread slippage on a subsequent roll forming a relaxing zone.

References Cited UNITED STATES PATENTS 400,694 4/1889 Lehmann 57-86 2,800,762 7/1957 Wiirmli 57--34 X 3,137,987 6/1964 Potts 57-93 X 3,149,451 9/1964 Benson et a1. 57-22 3,325,985 6/1967 Bucher 5793 DONALD E. WATKINS, Primary Examiner US. Cl. X.R. 57--l56, 22, 159 

